1. Field of the Invention
The invention relates to a fuel cell assembly structure, which especially refers to a simple structure that can be easily produced and dissembled with reduced production cost and increased product competitiveness.
2. Description of the Prior Art
Fuel cell is a device that uses fuel (hydrogen, oxygen as most common) to conduct chemical reaction and directly converts chemical energy into electrical energy. Since it has high conversion efficiency, wide range of fuel selection, no hazard in reaction process and useable by-product (water), it is generally considered as an alternative energy to fossil fuel.
In the principle of solid oxide fuel cell, the oxygen atom at cathode receives electrons by means of catalytic effect to turn into oxygen ion in reduction reaction. The oxygen ion is transported through electrolyte to anode and reacts with the fuel to produce water. At anode, oxidation reaction occurs and electrons are released and transported through an external loop back to cathode. At the same time, energy is supplied to the load. The only product (emission) from fuel cell is water. The above “hydrogen” fuel can come from any hydrocarbon, such as natural gas, methane, electrolysis of water, biogas . . . etc. Since the technology utilizes the chemical reaction between hydrogen and oxygen to generate electric current and water. There is absolutely no pollution and no issue of lengthy charging time with traditional battery. In a commercial fuel cell structure, key components like anode, cathode and electrolyte between the two electrodes form a membrane electrode assembly after a spray coating process and a flow field plate is added to their outer side. Thus, a single cell module is assembled. But because a single cell module produces a very limited amount of electrical energy (voltage, current). In a practical application, it needs serial connection of cells (or cell module) to increase output voltage and parallel connection to increase output current to achieve outputs in a practical level. In a commonly seen structure of fuel cell, one uses glass ceramic materials on the connection plate and the framework to form a specific flow field space and maintain airtightness. However, such a structure is fragile, rarely useful, and hard to repair interiors and lower maintenance cost. The other is to put a plurality of previously mentioned cell modules in the housing and a conductive connection plate between the cell modules, which are then connected serially. Since each cell module needs introduction of hydrogen and oxygen from outside to pass anode and cathode, flow channels are needed in the housing as passages for hydrogen and oxygen. One common method is to distribute a plurality of protruding holes around anode and cathode and allow different holes to connect to the anode and the cathode. When a plurality of cell modules is stacked, all the holes are connected to each other and from a flow channel to supply hydrogen and oxygen. However, such structure (a plurality of holes around anode and cathode) lacks design for restriction and positioning at edge, so the accommodating space inside the housing lacks the shape that fits. As a result, since the connection and positioning between cell modules is not easy, it increases the difficulty in assembly. Besides, the single module product that lacks integration is hard to disassemble and replace components and therefore the cost for maintenance, repair and usage too high to be competitive and to offer economic benefits.
In view of the above drawbacks with traditional fuel cell, the inventor has sought improvement over the above drawbacks and come up with this invention.